System Engineering and CG. Conceptual Graphs Home Page. Conceptual graph. Conceptual graphs (CGs) are a formalism for knowledge representation.
In the first published paper on CGs, John F. Sowa (Sowa 1976) used them to represent the conceptual schemas used in database systems. Laws, Facts, and Contexts. John F.
Sowa Abstract. Leibniz's intuition that necessity corresponds to truth in all possible worlds enabled Kripke to define a rigorous model theory for several axiomatizations of modal logic.